Circuit breaker with liquid or gas blow-outs



June 5, 1934. CLERC 1,961,475

' CIRCUIT BREAKER WITH LIQUID 0R GAS BLOW-OUTS Filed Feb. 25, 1933 3Sheets-Sheet 1 Fig. 1 3

\ a (70.? Open June 5, 1934. LERC 1,961,475

CIRCUIT BREAKER WITH LIQUID OR GAS BLOW-OUTS Filed Feb. 25, 1935 .5

3 Sheets-She t 2 F 99 7* e 1934. f A. CLERC CIRCUIT BREAKER WITH LIQUID0R GAS BLOW-OUTS June 5,

3 Sheets-Sheet 3.

Fil9 i Feb. 23, 1933 Patented June 5; 1934 CIRCUIT BREAKER WITH LIQUID0R BLOW-OUTS GAS Andr Clerc, Villeurbanne, France, assignor to AteliersDe Constructions Electriques De Delle,

Paris, France Application February 23, 1933, Serial No. 658,085 a InGermany February 22, 1932 19 Claims.

(Granted under thc'provisicns of sec. 14, act 6:

March 2, 192

It is known that when an arc flowing between two electrodes is blown bya compressed gas, such as air for example, it is lengthened out in thedirection of the blast and tends at the same time to escape from same.In high tension currents this lengthening of the arc in no wayfacilitates its extinction; it provokes on the contrary an unnecessaryincrease in the energy dissipated in the apparatus, thus hindering theextinction and increasing the deteriorations of the extinction chamber.

The object of the present invention is to-reduce the electric energydissipated during the extinction to a minimum value consistent with thesatisfactory operation of the circuit-breaker and further to eliminatethe effects of the back pressure this energy is still capable ofcreating. These two points immediately lead to an important reduction inthe energy to be imparted to the blowing out fluid without efiiciency. v

The energy dissipated by an electric arc flowing in a gaseous mediummaintained at constant pressure is proportional to the length of the arcand to the intensity of the current flowing through it as soon as thisintensity exceeds some ten amperes. It follows that at constant pressurethe energy in an are carrying a given current depends only on itslength. In order to reduce this energy to as low as a value as possibleit is consequently necessary that this are be very short. As on theother hand the specific energy 'or" an are (that is to say, at constantintensity, the voltage of the arc per unit length) increases with thepressure of the gas blast,.i t is necessary that this pressure be aslowfas possible. Thus in the case of a compressed air blow out in whichthe are usually flows in atmospheric air, the pressure of the air blastshould be equal or very slightly superior to that of the atmosphere.

The present invention permits the realization of these results. Itrelates to an electric circuitbreaker in which the arc is extinguishedby the blast of a liquid or gaseous fluid characterized in that one ofits contacts or an electrode connected to it and an extremity electrodeconnected to the other contact are disposed in the stream of extinguishing fluid and preferably in the central zone of this latter insuch manner thatthe line joining their opposed extremities isapproximate-- ly parallel to the flow of the blast. It is advantageousto give to the extremity electrode as well as to the electrode to whichit is opposed a form longated in the direction of the blast. In-

reality, an are emerging from the extremity of diminishing its anelectrode in the form of a metallic rod tends to assume the direction ofthis rod just as would ajet of water issuing from a nozzle. Consequentlyan arc whose points or origin are disposed on the opposite extremitiesoftwo elongated electrodes situated alonga stream line of the blast shouldalso assume a straight line direction. On the other hand it also seemsopportune to dispose the common axis of the two opposed electrodes inthe centre of the extinguishing blast where its action is mosteffective.

Finally it is well to note that the distance between the extremityelectrode on the one hand and the contact not connected to thiselectrode or the electrode of opposite polarity connected to thiscontact on the other hand should preferably be greater than the maximumspacing between the two contacts.

The annexed drawings show several embodiments of the object of theinvention.

Figs. 1, 2, 3, 5, l4 and 17 show in vertical section six applications ofthe invention to compressed gas circuit-breakers.

Figs. 4 and 6 are horizontal sections through the lines X-X and Y--Y inFigs. 3 and 5, and Fig. 18 is a plan view of the circuit-breaker shownin Fig. 17.

Figs. 7 to 13 show on a larger scale several alternatives of a detail ofthe object of the invention,Figs. 11 and 13 being plan views of thedetails shown in Figs. 10 and 12.

Finally Figs. 15 and 16 show in vertical section two applications of theinvention to liquid blow out circuit-breakers.

In Figs. 1 to 5, 14 and 17, the fixed contact of the circuit-breaker isindicated by 1 and the movable contact by 2. These contacts are disposedin the interior of a blast pipe 3 through which the extinguishing gas isinjected in the direction indicated by arrows.

In Figs. 1 and 2 the fixed contact 1 is electrically connected to anextremity electrode 1' disposed a certain distance away from thecontacts in the centre of the extinguishing blast. In Fig- 1 theelectrical connection 4 between the electrode 1 and the fixed contact 1ls'disposed on the outside of an insulating chimney 5, whereas inFig. 2this connection is disposed chiefly in the interior of the chimney 5 andcould even be entirely so disposed within the zone of in fluence of theair blast.

In Fig. 5 the insulating chimney 5 is partially suppressed and replacedby metallic walls 6 constituting in themselves both the blow out chimneyand the electrical connection between the indicated by full and dottedarrows.

fixed contact and the extremity electrode 1' fixed to the outlet orificeof the metallic .chimney 6. This'metallic chimney which may becylindrical or have any widened out shape is preferably constituted by aconically shaped tube which may eventually be provided on its lateralsides with circular openings '7 or with elongated slits allowing theinterior of the chimney to communicate with the atmosphere. The chimneycould also be constituted by a cylindrical or widened out cage the barsof which are preferably disposed in parallel direction to the flow ofthe extinguishing blast. This latter disposition is realized in thedevice shown in Figs. 17 and 18.

In Figs. 1 and 2 the chimney is entirely open at its upper extremity,the extremity'electrode being situated in the interior of the chimney. nthe contrary in Figs. 3. 5, 14 and 17 the extremity electrode isdisposed at and connected to the outlet of the metallic chimney. Itforms ahead to the chimney in the embodiments shown in Figs. 3 and 14,whereas in the embodiments of Figs. 5 and 17 the extremity electrode 1'is constituted by a number of horns directed radially towards the 'axisof the chimney.

When the extremity electrode constitutes the hood of a metallic chimney,this hood is of course provided with openings 8 allowingthe evacuationof the extinguishing gases. These openings can be uniformly distributedover the whole of the hood, however it seems preferable to have in thecentre of the hood a large opening 9 allowing the arc to emerge to, agreater or less extent outside the chimney. The point 'of origin of theare located on the edge ofthe opening, situated itself in the centre ofthe extinguishing blast is in this manner efficiently swept by the blastof gas.

--can bepear shaped with section diminishing in the direction of theblast. .The line joining the axes of the electrodes 1" and 2' coincideswith the axis of the chimney and with the axis of the extinguishingblast.

On the other hand, one or several intermediate electrodes 10 can bedisposed between the extremity electrode 1' and the arcing contact 2'along the central zone of the extinguishing blast and connected betweenthemselves as well as with the arcing contact 2 by means of resistances11 of low ohmic value. These intermediate electrodes, in the same manneras the extremity electrodes of Figs. 1 and 2, are constituted by hollowcylinders of revolution, the half sections of which are pear shaped. Theshape of this electrode is clearly shown in Figs. 10 and 11 in which twodirections of the displacement of thegases are If needs be thiselectrode can surround a central member 12 as shown in Figs. 12 and 13.-Other alternative electrodes are represented in Figs. '7 to 9, thatshown in Fig. 9 being particularly applicable to the intermediateelectrodes and to the arcing contacts 2'. It will be noticed that thestem holding these electrodes is enveloped in an arc resisting sleevepreferably of insulating material,

Finally in the embodiment of Fig. 5 the chinoney 6 is further surroundedby a chamber 13 the outlet of which is constituted by a metallic plateor metallic cylinder cooling device 14 disposed in front of theextremity electrode. It is further well understood that the extremityclectrode need not essentially be connected to the fixed contact butthat it can equally well be connected to the movable contact. In thiscase, the fixed contact will preferably be connected to an electrodedisposed in like manner to that shown by 2 on the drawings.

The operation of these devices is as follows. At the instant ofseparation of the contacts 1 and 2' an arc is struck between them. Thisare is immediately blown by the gaseous blast and lengthens in thedirection of the blast to such an extent that in the embodiments shownin Figs. 1 to 5 and 17 it almost immediately reaches the electrode 2; atthis instant the portion of the are between 2 and 2 is extinguished andthere only remains the arc 1, 2' disposed transversely to theextinguishing blast. The gases ionized by the are are swept by the blastin such manner that a part of these gases is driven between theelectrodes 1 and 2. At this instant takes place a transfer of the are l,2' upon the electrodes 1', 2'. There thus only remains a straight arcsituated in the axis of the extinguishing blast, an arc whose length islim ited by the distance 1, 2 and which is very rapidly extinguishedunder the influence of the gas blast.

The phenomenon of the transfer of the are above referred to explainsitself in the following manner: the are 1, 2 being disposed transverselyto the extinguishing blast (blast of air) in a zone in which this latterhas a very powerful cooling and deionizing effect, the energy it absorbsis very great compared with that of a stable arc in a quiet gas or withthat of an are 1', 2 flowing between two electrodes situated one behindthe other in an axial air blast. This increment of energy dissipated bythe are l, 2' results in a considerable increase in the arc voltage perunit length, and this to such an extent that it is easy to conceive thatthe are 1, 2' is far more unstable than that which one tends to strikebetween the central arcing contact 2 and the extremity electrode 1';this in spite of the fact that the distance between these two latterelectrodes is considerably greater than that between the contacts.

Oscillagraphic and high speed cinematographic investigationshave shownthe cause an arc to flow between 1' and '2' by the blowing of the gasesof an are originally struck between 1 and 2-. It is evident that theoriginal transverse arc will only extinguish itself when its gases havereached the extremity electrode 1'. There is consequently no intervalremarkable facility and rapidity with which it is possible to of timebetween the striking .of the are on' blast on the one hand upon thearcing contact 2 and on the other upon the extremity elec v trode 1'. Inthe device illustrated in Fig. 1 the arc assumes the form of a bow withpoints of origin fixed to, the contact 1 and to the arcing contact 2'whereas the apex of the bow reaches almost instantly the extremityelectrode 1'. At this instant the left hand portion of the bowextinguishes itself and the remaining portion forms a straight aresituated in the. axis of the extingushing blast, this right hand arebeing very rapidly suppressed.

In the other embodiments, on the contrary, one of the points of originof the arc displaces itself along the connection 4 or along the interiorof the metallic wall of the chimney 6, the second point of originremaining fixed either on the contact 2 or on the arc ng contact 2'. Theare apparently pivots about the arcing contact 2' until it reaches theaxial position in which it is rapidly extinguished. It is to be notedthat this displacement of the-arc is realized .with extreme rapidity. A

The length of the arc is thus strictly limited as it cannot extend toany great extentbeyond the extremity electrode.

- When the arc is extinguished by a liquid jet, water or oil forexample, the construction and operation of the circuit-breakers areanalogous.

The Figs. 15 and 16 of the annexed drawings show two such embodiments.

In these figures one recognizes the fixed contact 1 and the movablecontact 2, the direction of displacement of which on opening isindicated by an arrow' 15. These contacts are located in a vessel filledwith a liquid, water or oil for example. Facing the contacts'is dsposedthe nozzle of an injection tube 3 terminating in a piston 17 capable ofprojecting against the contacts 1 and 2 a jet of liquid whosetheoretical zone of action is indicated by 18.

The fixed contact is connected to an arcing contact 1', whereas themovable contact is connected to an extremity contact 2', the elements 2'and 1' being disposed in the central zone of the extinguishing stream.

As shown in Figs. 15 and 16 the blow out may be vertical in upwarddirection or may be horizontal; it may equally be disposed in any otherdirection, for instance vertically in downward direction.

The operation of these devices is indicated by dotted lines showing theprogressive displacement of. the arc up to its final position in thecentre of the extinguishing stream.

The word electrode used in this specification is intended to mean fixedmembers which are connected to a conductor under tension, but whichmembers are never in mechanical engagement with a movable contact of thebreaker.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:-

1. An electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thesecontacts transversely to their direction of motion, a fixed electrodeconnected to one of the-contacts and a fixed extremity electrodeconnected to the other contact, the extremity electrode being situatedbehind the electrode considered in the direction of the said jet and theline joining the opposed extremities of the two electrodes being locatedin the central zone of the extinguishing jet and approximately parallelto its axis.

2. An electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thecontacts transversely to their direction of motion, a fixed electrodeconnected to one of the contacts and a fixed extremity electrodeconnected to the other contact, the extremity electrode being situatedbehind the electrode, considered in the direction of the said jet, at agreater distance than the maximum separation of the two contacts, andthe line joining the opposed extremities of the two electrodes beinglocated in the central zone of the extinguishing jet and approximatelyparallel to its axis.

3. An electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thesecontacts transversely to their direction of motion, a fixed electrodeconnected to one of the contacts and a fixed extremity electrodeconnected to the other contact, these electrodes having an elongatedform disposed along a common axis parallel to the extinguishing jet.

4. An electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thesecontacts transversely to their direction of motion, a fixed electrodeconnected to one of the contacts and a fixed extremity electrodeconnected to the other contact, the extremity electrode being situatedbehind the electrode considered in the direction of the extinguishingjet, and the line joining the opposed extremities of the two electrodesbeing situated approximately in the axis of the extinguishing jet.

5. An electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thesecontacts transversely to their direction of motion, a fixed electrodeconnected to one of the contacts and a fixed extremity electrodeconnected to the other contact by means of a conductor almost completelyinsulated from the arc, the extremity electrode being situated behindthe electrode considered in the direction of the extinguishing jet andthe line joining the opposed extremities of the two electrodes beingapproximately parallel to the extinguishing jet.

6. An electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thesecontacts in view of lengthening the arc, a fixed electrode connected toone of the contacts and a fixed extremity electrode connected to theother contact, one end of the extremity electrode extending very nearthis latter contact in the path of the blown arc, thev other end of thisextremity electrode being situated behind the electrode considered inthe dirtction of the extinguishing jet, and the line joining the opposedextremities of the two electrodes being approximately parallel to thextinguishing jet. I 7. An electric circuit-breaker comprising tworelatively movable contacts, a chimney with conducting interior surface,means for projecting a gas blast against these contacts and into thischimney, an electrode situated in the central zone of the extinguishingblast and being connected to 5 one of the said contacts; and anextremity electrode situated at the outlet of the chimney andterminating in the central zone of the gas blast, this extremityelectrode being connected to the conducting surface of the chimney andthis surg,

face being connected to the other of said contacts.

8. An electric circuit-breaker comprising a fixed contact and a movablecontact to open the circuit, a chimney with conducting interior surface,disposed around the common axis of these contacts, means for projectinga gas blast against these contacts and into this chimney in thedirection of motion of the movable contact, an extremity electrodesituated at the outlet of the said chimney, this extremity electrodebeing electrically connected to said chimney and to the fixed contactand terminating in the central zone of the extinguishing jet.

9. An electric circuit-breaker comprising two relatively movablecontacts, a chimney with conducting interior surface, this chimney beingterminated, at one end, by a metallic hood forming an extremityelectrode and comprising a central opening forming outlet of thechimney, means for projecting a gas blast against these contacts andinto this chimney, and an electrode situated in the central zone of thegas blast and being connected to one of the contacts, the other contactbeing connected to the conducting surface of the chimney and by thissurface to the extremity electrode.

10. An electric circuit-breaker comprising two relatively movablecontacts, a chimney with conducting interior surface, this chimney beingter-' minated, at one end, by a metallic hood forming an extremityelectrode and comprising a number of openings forming outlets of thechimney, means for projecting a gas blast against these contacts andinto this chimney, and an electrode situated in the central zone of thegas blast and being connected to one of the contacts, the other contactbeing connected to the conducting surface of the chimney and by thissurface to the extremity electrode.

11. An electric circuit-breaker comprising two relatively movablecontacts, a chimney with conducting interior surface, this chimney beingterminated, at one end, by a metallic hood forming an extremityelectrode and comprising a number of perforations and a large centralopening forming outlets of the chimney, means for projecting a gas blastagainst these contacts and into this chimney, and an electrode situatedin the central zone of the gas blast and being connected to one of thecontacts, the other contact being connected to the conducting surface ofthe chimney and by this surface to the extremity electrode.

12. An electric circuit-breaker comprising two relatively movablecontacts, a chimney with conducting interior surface, this chimney beingterminated, at one end, by a metallic horn directed towards the axis ofthe chimney and forming an extremity electrode means for projecting agas blast against these contacts and into this chim ney, and anelectrode situated in the central zone of the gas blast and beingconnected to one of the contacts, the other contact being-connected tothe conducting surface of the chimney and by this surface to theextremity electrode.

13. An electric circuit-breaker comprising two relatively movablecontacts, a chimney with conducting interior surface, this chimney beingterminated, at one end, by several metallic horns directed radiallytowards the axis of the chimney and forming extremity electrodes, meansfor projecting a gas blast against these contacts and into this chimney,and an electrode situated in the central zone of the gas blast and beingconnected to one of the contacts, the other contact being connected tothe conducting surface of the chimney and by this surface to theextremity electrode.

l4.- An electric circuit-breaker comprising two relatively movablecontacts, a metallic chimney with inlet and outlet openings, openings atthe lateral sides of this chimney, means for project ing a gas blastagainst these contacts and into this chimney, an electrode situated inthe ntral zone of the gas blast and being connected to one of the saidcontacts, and an extremity electrode situated at the outlet opening ofthe said chimney and terminating in the central zone of the gas blast,this extremity electrode being connected to the metallic chimney and tothe other of said contacts.

15. An electric circuit-breaker comprising two relatively movablecontacts, a cage formed by metallic bars and connected to one of thesecontacts, means for projecting an extinguishing jet against thesecontacts and into thiscage in parallel direction to the bars of the saidcage, an electrode connected tothe other of these contacts and situatedin the central zone of the extinguishing jet, and extremity electrodesfixed at the outlet of the said cage and terminating in the central zoneof the extinguishing jet.

16. An electric circuit-breaker comprising two relatively movablecontacts, a chimney with conducting interior surface, a chambersurrounding that chimney, means for projecting a gas blast against thesecontacts and into this chimney, an electrode situated in the centralzone of the gas blast and connected to the one of said contacts, 1 anextremity electrode situated at the outlet of the chimney andterminating in the central zone of the gas blast, this extremityelectrode being connected to the conducting chimney and this latter tothe other of the said cont'acts'and a 1 cooling device for the escapinggases, this device being. situated behind the extremity electrode seenin the direction of the gas blast and constituting the outlet of thesaid chamber.

' 17. Ar. electric circuit-breaker comprising two relatively movablecontacts, means for projecting a jet of extinguishing fluid on thesecontacts transversely to their direction of motion, an elec-- trodeconnected to one of the said contacts, in-

termediate electrodes connected by means of resistances one to anotherand to this latter contact, an extremity electrode connected to the"other of the said contacts, these various electrodes being fixed andthe line joining their opposed extremities being located in the centralzone of the extinguishing jet and approximately parallel to its axis.

18. An electric circuit-breaker comprising two contacts, fixedelectrodes connected each to one of these contacts, means for projectingan extinguishing jet against these contacts and against theseelectrodes, these electrodes being constituted by hollow cylinders ofrevolution the half section of which is pear shaped, these electrodesbeing situated one behind the other in the axis of the extinguishingjet.

19. An electric circuit-breaker comprising two contacts, fixedelectrodes connected each to one of these contacts, means for projectingan extinguishing jet against these contacts and against 14h theseelectrodes, these electrodes being constituted by hollow cylinders ofrevolution, a metallic rod being-fixed in the interior of each of thesecylinders, these rods being disposed in the axis of the extinguishingjet. ANDRE CLERC.

